


Sleepwalk

by antihero_antisocial



Category: Assassin's Creed - All Media Types, Kuroshitsuji | Black Butler
Genre: M/M, Multi, My First Fanfic
Language: English
Status: In-Progress
Published: 2021-01-02
Updated: 2021-01-23
Packaged: 2021-03-12 08:22:56
Rating: Not Rated
Warnings: Graphic Depictions Of Violence
Chapters: 5
Words: 3,635
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28507401
Author URL: https://archiveofourown.org/users/antihero_antisocial/pseuds/antihero_antisocial
Summary: A new, strange scourge roams the streets of Victorian London. It's victims seem to be both the victim and the murderer. The crime scenes are essentially indecipherable. While the Queen's Guard dog investigates, the Frye twins face a new, terrifying enemy.
Relationships: Frederick Abberline & Original Non-Human Character(s), Frederick Abberline/Jacob Frye, Sebastian Michaelis & Ciel Phantomhive
Kudos: 3





	1. Prologue

**Author's Note:**

> Warning: This has disturbing violence.

**Whitechapel, 1889**

The woman was unaware of it. It was watching this human sleep for what felt like days. But it had the patience. The human was in her dreams currently. Now it is time. Soft silver light seemed to glow within the humans veins. The human stood up, still asleep. The human shell contains the monster's will. Her body transformed slightly. Her eyes were no longer her own. They were silver with narrow line splitting each eye in half.

She travelled down the halls of her home, collecting a knife. The wood creaked with each step the monster made. It crept into the room containing a second human, who seemed to be in a deep sleep. A large knife silt his throat. She butchered the man. Her knife opened up his stomach and in one quick bite, the man's liver was gone. The starving monster watched as the human broke free of its spell. The human was weeping. 

The monster made a creaking noise by walking on a particularly annoying part of the floor. The woman immediately turned around and screeched. It growled at the loud noise and bared its teeth. The human was trying to escape the house. Why was she trying to escape? Not wanting its power to be gone, the monster pounced on her. It sunk it's fangs into her throat and ripped it out. The blood was delicious and the power even more so.

It couldn't wait for more of these feasts. All of it was intoxicating. This night was the first of many nights where it would feast.


	2. Chapter 1

**Notes for the Chapter:**

> This takes place after season 1 of Black Butler. In this fic Fred doesn’t have a fiancé or a child and he survives. Also I apologize if the characters were ooc.

**Whitechapel, The next day**

Arthur Randall was perplexed, to say the least. The scene was sanguinary. Blood soaked the house's hallway. A young man with messy ginger hair was staring at the female's body. "Abberline!" Arthur shouted. "Mind telling me what happened here?" The commissioner was feeling very irritable today. "The victims are the 32 year olds Adriana and John Mullins," Abberline reported. "They are twins. John died of a slit throat whilst Adriana has died of a punctured windpipe. It looks like she had slit his throat and was then mauled by an animal."

Randall looked skeptical. "If they were mauled by an animal then there would be paw prints and fur." Arthur said. The old man looked down at the corpse of Adriana. There was a large knife just a foot away. It looks like it had fallen out of her hand. "It looks like the woman didn't work alone. Perhaps she had a partner in crime who betrayed her. "Officers, get these bodies to the coroner. Detectives, canvas for witnesses, establish a time frame, and bring me a suspect. Find out who were the last people to see these two alive." The orders were met with 'yes sir' by all the police officers present. 

Frederick's coworkers hurried off to do what Randall commanded. Frederick was still staring at Adriana's body. His stare was unusually blank. "Abberline, are you listening?" Randall asked, annoyed. It wasn't like Abberline to ignore him like that. 

"Yes, I'm listening, sir," Abberline replied, a bit slowly. "It's just the smell. It's quite chemically noisome, isn't it?" Arthur’s frustration grew stronger. There was no strong chemicals here.

"Do you have a theory about the bite yet?" Arthur asked. The detective looked at Randall.

"I'm trying to think of what could've caused this bite. Maybe a trained dog?" Replied Abberline. 

"Maybe," Said Randall. "What about the woman?"

"I think she was working with someone she knew," Frederick stated. "If they were a stranger then she would've had a cleaner death. I think the attacker was angry at Adriana for some reason." 

"That does make sense," Randall said. "But we won't know more until the medical examiner goes over it. Go contact the next of kin."

"Yes sir!"


	3. Chapter 2

**Southwark**

It's a nice afternoon. It's sunny and there was a cool breeze. The street Jacob Frye is walking in is crowded with civilians and Blighters. Luckily he was able to blend in with the civilians. His target is Albie Vassell. Vassell still hadn't noticed him. _Good._ He quickly tackled Vassell and pinned his arm to his back. "Who do you think you are? Get your bloody hands away from me! Help!" The murderer cried. "Shhh. That's enough." He whispered to the Blighter. There were a couple more protests until they got to the top of the street. He shoved Albie into a carriage discreetly. Albie wasn't going peacefully although. "Get me out of here!" Vassell yelled to the nearby Blighters. Jacob climbed into the drivers seat and took hold of the reins. He shot off at full speed trying to get the Blighters off his tail. After a couple minutes of that he lost visual of the Blighters. _Now, off to Freddy._ It only took ten minutes to reach the meeting point under the train tracks. 

Freddy was waiting there with a police vehicle. "Hey there, Freddy," Jacob said casually. "One Albie Vassell for you."

"Is he alive?" Abberline said.

"Oh ye of little faith," Jacob assured him. "Yes, Vassell is alive." Abberline proceeded to hand him the money and drag Vassell into the police vehicle. Something about Fred seemed off though. He wasn't present, it was like he was listening to something far away. Which is weird because the man would never let himself get distracted from whatever is in front of him That's one of the the reasons he liked Freddy. If something was affecting Freddy then he wanted to know. "Something wrong, Freddy?"

"Huh? Oh. Nothing's wrong." Freddy responded. "Just a little preoccupied."

"Is it a case?" Jacob asked, trying to get more information.

"I'm concerned by the amount of times I've had to say this to you, Jacob, but that's classified." 

"Oh, come on, Freddy. You can tell me. I could lend a hand."

"There was a murder in Whitechapel. John and Adriana Mullins were murdered. John has a slit throat whist Adriana had a punctured windpipe. It was like an animal killed her." Fred explained. _That only half explains why Freddy is acting strange. An animalistic killing would be a disturbing sight but he's seen worse._ "Is there anything else?" Jacob asked.

"No, we're still waiting for the autopsy results." Abberline said.

"Well, tell me when you have more information. I'm gonna help you. I shall see you later, Freddy!" Jacob replied, leaving no room for objections by climbing back on to the driver's seat of his carriage. _Let's see what's in Whitechapel._


	4. Chapter 3

**Three days later at 1:00am, Abberline's apartment**

The dream he was having was strange. He was in a narrow hallway, eight corpses in front of him half-eaten. Among the corpses was Adriana Mullin's body and a couple more victims who had been killed by the same killer. Blood was flooding the hallway. Frederick resisted the urge to throw up. Fear was building up in his head. He noticed something causing ripples in the blood. _What the hell?!_ A large creature stood behind him. It had completely black eyes with narrow silver pupils. The monster looked like no animal he'd ever seen. It walked on four legs that reminded of him of a wolf. It had ram horns and was the color of tar. Black fur covered its back. He could see the ribs of the creature. Abberline became frozen with fear when he heard its stomach growl. _Oh_ _hell_ _no._ The blood was up to his knees and the creature's forearm. The monster tilted its head at him and stared at him. He braced for the worst when the monster moved towards him but didn't expect himself to wake up.

Frederick was sweating. That was the sixth time he’s had that dream this month. They were almost all the same. The only difference is that he knew the name of one of the corpses this time. _It's probably stress. It's only been two months since I almost died. I'll work on the case right now._ Speaking of his near death experience, he felt a sharp pain in his stomach return. He suddenly felt the presence of something else. Fred reached for bedside table and instead felt soft fur. All the alarms in his head went off. _Please don't be real. Please don't be real._

Fred looked at the bedside table and craned his neck to see the large canine. Enlarged glowing silver pupilsstared back at him. His hand was still on the creature's chest. It looked very hungry. "Please don't eat me," He whimpered. The creature made a humming noise before trying to get on the bed.

The bed sounded like it was dying when the strange hybrid creature got on the bed. He noticed the admittedly elegant wings folded on the animal's back. It chirped at him. **"** **Hunger."** A garbled voice told him. _I'm still sleeping. When I wake up, it will be day. This isn't real._ Frederick repeated to himself in his head. **"** **Very awake. Very real. Very hunger."** It looked at him expectantly.

 _It talks in broken english? More importantly, did it just TALK?_ Fred was freaking out. " **S** **omn is hunger."** The man composed himself. This creature, Somn apparently, wants food from him. He had no doubt in his mind that he would soon become Somn's meal if he didn't comply.

He got out of bed quickly. His back was never facing Somn the entire time. He proceeded to make his way to his icebox when he was sure it wouldn't eat him. There was only a leg of lamb in the icebox. _It'll have to do._ He brought the leg of lamb to Somn. He was expecting the creature to eat it then eat him. What he wasn't expecting was Somn eating the leg in one bite and looking satisfied. **"** **More."**

"That's all I have." 

**"All human have?"** The creature sounded surprised.

"You'll leave now right?" Abberline asked cautiously, not knowing if Somn could fully understand him.

 **"No. Human gave Somn food. Somn now stay with human."** The creature stated.

 _So this is why they say "never give a stray food". It seems that this creature is canine and intelligent enough to speak._ Fred's mind remembered the Adriana Mullin's murder and that he had seen this creature in the dreams about the murder. _T_ _he teethmarks that were found were canine. I should keep an eye on this unusual animal for now._ He can't have an animal in the building. His landlord will most likely kill him.

It then came to him, the supernatural is real! This greatly surprised Fred. He had never been particularly religious or spiritual. Did this mean Heaven and Hell were real? Anything seemed possible now that he's seen Somn. 

Somn looked satisfied with itself. It curled up on the bed, completely ignoring the bed's protests. _I'll just sleep on the couch._ He didn't want to find out what happens when he disturbs Somn. He got out of the bedroom and slept on the couch. The couch he was on was already uncomfortable but his injury made it even worse. Thus began a painfully uncomfortable night.

**7:00am**

Frederick woke up at a loud noise that came from the bedroom. When he entered the bedroom he saw that the alarm clock had been smashed by Somn. "What is your problem?" He yelled. **"Loud. Not good."** Somn grunted. "Right. I need to go to work." Abberline said, realizing the time.

 **"Hunting prey? Human injured."** Somn questioned.

"No, I am not. I spent enough time recovering. I shall do my job." Fred answered.

 **"So you hunt prey. If not, I hunt. Either way we feast."** The canine creature said.

"I'll hunt. Just do not hunt and I'll come back with food," Fred said quickly, not wanting the creature to hunt humans. He still wasn't exactly sure what this thing's intentions were." I need to get ready now." The creature huffed. About thirty minutes later, Frederick got out the door. **"Where are we going?"** Somn had appeared behind him. 

"We aren't going anywhere. _I'm_ going to work and you are staying in the apartment." He scolded quietly.

 **"Other humans prey. Cannot see Somn wings or horns. Not worthy. I look like common wolf to them."** Somn said bluntly.

"Exactly. Do you see any human with a wolf beside them? No. Maybe a dog, not a wolf." Abberline responded.

 **"Why wish to be like prey? Why be unprotected and injured when can be protected?"** Somn questioned. 

"You're not coming." Abberline said, completely ignoring Somn's questions. 

**"Somn is coming. Somn protect human."** Not seeing a point in arguing any further, he continued on his way to work.

**8:00am, East End, 1889**

When he arrived at the crime scene, he noticed three people. Arthur Randall who looked very annoyed. Ciel Phantomhive, and Sebastian Michaelis making their way to Randall who was in front of the bodies. He approached one of the constables and asked him who the victims were this time. **"Why are you visiting devoured prey? What is the purpose?"** Somn grumbled. The constable didn't seem to notice the fact that Somn just spoke. _Everyone else can't hear Somn. Also did Somn just say devoured?_ "Excuse me Detective, but is that a wolf?" The constable was glancing at Somn.

"Yes. It's tame though so don't worry." Abberline said, secretly hoping that was true. 

"Okay. Here's the clipboard." The constable nervously said. Abberline read the notes and made his way to the bodies. The victims were the 23 year old Charles Goldstein and the 29 year old Oliver Nelsen. Same M.O as the previous victims. There was something strange in the air, it smelt like chemicals just like the previous crime scenes. **"Get out of here. Demon here. Demon means danger,"** Somn said urgently. **"Somn fight it."**

If Somn exists then that means that the chance of a demon was likely. _But I don't see a demon or anyone I don't recognize._ "Abberline, why is there a wolf with you?" A voice pulled him out of his thoughts. The voice belonged to his superior, Randall. "The wolf is a police dog." Frederick responded. Randall looked unamused.

"It better be tame," Sir Arthur said, sounding exasperated. "Is it even focusing?" The wolf in question wasn't sniffing anything. Somn was staring warily right at Sebastian Michaelis, who looked just as wary. **"Tall one is demon."** Somn promptly informed him. Fred looked at Michaelis, really looked at him, and realized a dark aura around him. Sebastian then looked at Fred suspiciously. Perhaps Somn's claim had some merit.

"Honestly I have no idea. One of the constables recommended using this wolf." Fred quickly came up with a cover. "Since the bite marks are canine, maybe a fellow canine would sniff it out." Frederick could tell that out of the three people talking, Sir Randall was the only one who was fooled by that. Ciel had his usual mask on whereas Sebastian was looking skeptical. "Sir Arthur, do you have anymore information?" Ciel asked Fred's superior.

"I'm afraid that's all you're getting, Phantomhive." Sir Arthur said, shooting Abberline a glare. Fred had unfortunate knowledge as to why his boss hated the Phantomhives. Which was why Fred had to give Ciel the information instead of Randall. "The victims are Charles Goldstein and Oliver Nelsen. Same modus operandi as the previous victims. A canine punctured Charles's windpipe after Charles killed Oliver. The livers, pancreas, and hearts are all missing, presumably eaten. There is also a chemical smell emitting from the bodies." Abberline reported. Ciel had a flicker of curiosity in his eyes that quickly disappeared. _Does he know something?_ He didn't have to look to know that Randall was giving him a murderous glare.

 **"** Thank you, Detective Abberline." Ciel's gaze lingered on Somn before leaving. When Fred turned to face Randall, he could tell he was in deep shit. **"Somn hate this old one.** **H** **e will die."** Somn growled. _Please don't._ "Abberline, you are on door duty." Sir Arthur deadpanned. Frederick internally groaned. Today would be a long day.


	5. Chapter 4

**Summary for the Chapter:**

> Sebastian and Ciel know Somn is bad news. Abberline is gullible. Jacob is confused.

His master had been acting different. Ever since that Abberline saved the young master, the human had become softer. He had spared his enemies. It is clear that the detective had a great impact on Sebastian's master. He could tell that Ciel was concerned about the detective, who was still walking with a limp. It was a miracle that no one commented on Abberline's statement on the "chemical smell". Regular humans couldn't smell that so they would think that he was either joking or crazy.

Then there is that being was following Abberline around. A sentient winged beast was attached to that human like a parasite. _Depending on what the abomination's intentions are my master could get hurt_ _._ The young noble had seemed to figure out that something was fishy about the creature immediately. After all, a large abnormal wolf is not something you would expect to see in London. "Sebastian, do you know of a species that would do this type of thing?" Ciel asked as they entered the carriage. 

"I already know who has done this, young master. It is the strange wolf that was following Mr Abberline around," Sebastian replied. "But I'm afraid that it is no species I know of, my lord."

"What do you mean you don't know?" 

"It is supernatural and I've never heard of something quite like it." Sebastian dutifully answered. _The young master seems upset at this. I have to admit I'm quite perplexed at this point. It seems to have latched on to Mr Abberline, allowing him to have heightened senses. How is it able to do that?._ No normal human could've smelt that. It could be mutating the detective. Perhaps that is its power. "It is useful to know that it is attached to Mr Abberline. So much so that it has enhanced his senses." Sebastian said.

"So that chemical smell was actually there?" Ciel asked.

"Yes it was

"What was source of the smell?"

"It came from the brains of the victims."

Sebastian could see the wheels turning in his master's head. Outside the window he could see a young man in his 20s jumping from rooftop to rooftop. _How curious._ Humans really were fascinating. "Sebastian, get us to the Undertaker's shop."

"Yes, my lord."

**Outside the Goldstein apartment complex**

Abberline had been knocking on every door of every apartment in this complex. It was exhausting not that he'd ever admit it. **"Kill this one, human."** Somn had said at one point. Fred had almost said yes. He found himself getting more and more tired with each terrible minute. When he finished he had given Randall his notes. The commissioner had grumbled and yelled at him for giving Ciel information. Randall looked like he was about to punch Abberline. **"He rude. I kill him."** Somn had said. Somn let out a menacing growl before sinking his teeth into Sir Arthur's forearm. He and a couple other officers had to tear the wolf off of Randall. "GET THAT ANIMAL OUT OF MY SIGHT, ABBERLINE!" Randall had roared.

And that is how he ended up out of the building, in the alley. He was still trying to figure out how to get rid of this animal without being mauled to death. "So, Somn is there anyway you could uh leave?" He asked the wolfish creature. **"No. You are my new source of food. Soon to be vessel. Why waste hard work of searching?"** Somn said incredulously.

"Wait, vessel? How? And furthermore WHY?" Abberline panicked.

**"Once healed, Somn possess you. Somn much stronger with human voice box. And opposable thumbs."**

"Why?"

**"I just said strength?"**

"Let me rephrase that. Why in the world would you choose me?"

**"Not much cowardice. Lacks annoyingness. Not many would miss when leave. "**

"What do you mean no one will miss me?"

**"No family. No friends. A job with high mortality rate. Colleagues who dislike you. Wouldn't life as vessel be better?"**

"I have friends and a brother. No, life as a vessel would be terrible. Don't possess me."

**"Very few friends and a brother that is not seen. No attachment he has for you does he? I spare you from betrayal and loneliness. I get human body and food. We win."**

"I don't need your pity." Abberline all but growled. It's true that he doesn't see his older brother that often but that doesn't mean Edward hates him. He heard footsteps behind him and turned around. Jacob Frye was standing there, looking sort of amused. "Are you talking to a dog, Freddy?" Jacob asked. "You do know that he's not gonna talk back, right?" Fred blushed in embarrassment at that.

"I'm just talking to myself." _Shit, that's worse._ Frederick wanted to hit himself. Jacob chuckled. **"That one not your friend. Doesn't actually care."** _SHUT UP._ "Do you have any information about the case?" Frye asked.

"Jacob, the case is doing perfectly fine."

"Says the man who is talking to himself," Jacob said. "Just let me lend a hand. You get the credit while I do the work. It'll be like the bounties."

"No. Stay out of this case." Frederick said firmly. Fred had no way of knowing if Jacob knew that Ciel's butler was a demon or that the Queen's Guard-Dog was already investigating. Abberline didn't want Jacob hurt. Jacob looked at him strangely before saying, "Whatever you say Freddy." and leaving by disappearing into the crowd outside of the apartment complex.

**"Are you sure he cares as much as you?"** Somn asked. _I'm fine. My brother cares. I have friends. Count your blessings, Fred._ **"Listen to me, you are not fine. No one cares except me. I help. I care."** Frederick knows he shouldn't listen to Somn, but he knows that it is not lying.


End file.
